Frequency, spacing, and outcome of pregnancies subsequent to primary cesarean childbirth.

A prospective study was conducted to determine the frequency, spacing, and outcome of pregnancies that occur subsequent to primary cesarean childbirth. A cohort of 5513 women, pregnant for the first time and with these pregnancies terminating with a live birth via cesarean childbirth, were followed for 5 years with use of the vital records registration system of the New York State Department of Health. Also followed was a group of women whose first pregnancy terminated with a live birth via vaginal delivery. The cesarean childbirth study group was found to have had 11% fewer pregnancies terminating during the follow-up period than did the vaginal delivery group. Subsequent live births among the cesarean delivery study group were, on the average, 1 week shorter in gestation and lower in birth weight than those of the vaginal delivery group. However, there was no excess of very low- or low-birth weight infants among the cesarean delivery study group. There was no difference between study groups in the spacing of subsequent pregnancies.